From patchwork Mon Oct 23 08:02:37 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Billy Tsai X-Patchwork-Id: 13444907 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 82303C0018A for ; Fri, 3 Nov 2023 18:52:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:Message-ID:Date:Subject:CC :To:From:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:References: List-Owner; bh=ZuUHU1Mw8bCrWvx8KxIMoUKcmOOY0sDt6qZ8eBDFNTk=; b=qFVukOVmOVuWHK L4jXU34wu2pYVenB+rP5rt6XZJGdiEnJkYZ3xmSl7J+ARtw832vXPfFBNK0hkwUfhaRJUHwCNpNnn gVlZYzUQNXaW4di/HOwMrultgRY2bGCJEclcQfDMMzG/WIQeROj/lj0VN6kS+nwQflr8hGPrNK2Gv xz5bsII4OA5nsF2kIkGJaT4itAhJTPMBq6Cr09Nw2X6WT6F5sv5c1IDvoq9I/ghzc64XAMA3bFHnF 3n0xkBSqsAh+keFgWDQmXYoMaUKOopLTzbz8GtmRqfVL3S0963msNRsFFuA6h96Vj9TDHT+LTJeil PiAEyKV7DGNMQP+f75Kw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1qyzHf-00BzhD-0r; Fri, 03 Nov 2023 18:52:43 +0000 Received: from mail.aspeedtech.com ([211.20.114.72] helo=TWMBX02.aspeed.com) by bombadil.infradead.org with esmtps (Exim 4.96 #2 (Red Hat Linux)) id 1qupte-006hdB-14 for linux-i3c@lists.infradead.org; Mon, 23 Oct 2023 08:02:48 +0000 Received: from TWMBX02.aspeed.com (192.168.0.24) by TWMBX02.aspeed.com (192.168.0.24) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Mon, 23 Oct 2023 16:02:38 +0800 Received: from twmbx02.aspeed.com (192.168.10.10) by TWMBX02.aspeed.com (192.168.0.24) with Microsoft SMTP Server id 15.0.1497.2 via Frontend Transport; Mon, 23 Oct 2023 16:02:38 +0800 From: Billy Tsai To: , , , CC: Subject: [PATCH v1] i3c/master/mipi-i3c-hci: Fix a kernel panic for accessing DAT_data. Date: Mon, 23 Oct 2023 16:02:37 +0800 Message-ID: <20231023080237.560936-1-billy_tsai@aspeedtech.com> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 Received-SPF: Fail (TWMBX02.aspeed.com: domain of billy_tsai@aspeedtech.com does not designate 192.168.10.10 as permitted sender) receiver=TWMBX02.aspeed.com; client-ip=192.168.10.10; helo=twmbx02.aspeed.com; X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20231023_010246_389420_E8A23B28 X-CRM114-Status: GOOD ( 10.59 ) X-Mailman-Approved-At: Fri, 03 Nov 2023 11:52:41 -0700 X-BeenThere: linux-i3c@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-i3c" Errors-To: linux-i3c-bounces+linux-i3c=archiver.kernel.org@lists.infradead.org The `i3c_master_bus_init` function may attach the I2C devices before the I3C bus initialization. In this flow, the DAT `alloc_entry`` will be used before the DAT `init`. Additionally, if the `i3c_master_bus_init` fails, the DAT `cleanup` will execute before the device is detached, which will execue DAT `free_entry` function. The above scenario can cause the driver to use DAT_data when it is NULL. Signed-off-by: Billy Tsai --- drivers/i3c/master/mipi-i3c-hci/dat_v1.c | 29 ++++++++++++++++-------- 1 file changed, 19 insertions(+), 10 deletions(-) diff --git a/drivers/i3c/master/mipi-i3c-hci/dat_v1.c b/drivers/i3c/master/mipi-i3c-hci/dat_v1.c index 97bb49ff5b53..47b9b4d4ed3f 100644 --- a/drivers/i3c/master/mipi-i3c-hci/dat_v1.c +++ b/drivers/i3c/master/mipi-i3c-hci/dat_v1.c @@ -64,15 +64,17 @@ static int hci_dat_v1_init(struct i3c_hci *hci) return -EOPNOTSUPP; } - /* use a bitmap for faster free slot search */ - hci->DAT_data = bitmap_zalloc(hci->DAT_entries, GFP_KERNEL); - if (!hci->DAT_data) - return -ENOMEM; - - /* clear them */ - for (dat_idx = 0; dat_idx < hci->DAT_entries; dat_idx++) { - dat_w0_write(dat_idx, 0); - dat_w1_write(dat_idx, 0); + if (!hci->DAT_data) { + /* use a bitmap for faster free slot search */ + hci->DAT_data = bitmap_zalloc(hci->DAT_entries, GFP_KERNEL); + if (!hci->DAT_data) + return -ENOMEM; + + /* clear them */ + for (dat_idx = 0; dat_idx < hci->DAT_entries; dat_idx++) { + dat_w0_write(dat_idx, 0); + dat_w1_write(dat_idx, 0); + } } return 0; @@ -87,7 +89,13 @@ static void hci_dat_v1_cleanup(struct i3c_hci *hci) static int hci_dat_v1_alloc_entry(struct i3c_hci *hci) { unsigned int dat_idx; + int ret; + if (!hci->DAT_data) { + ret = hci_dat_v1_init(hci); + if (ret) + return ret; + } dat_idx = find_first_zero_bit(hci->DAT_data, hci->DAT_entries); if (dat_idx >= hci->DAT_entries) return -ENOENT; @@ -103,7 +111,8 @@ static void hci_dat_v1_free_entry(struct i3c_hci *hci, unsigned int dat_idx) { dat_w0_write(dat_idx, 0); dat_w1_write(dat_idx, 0); - __clear_bit(dat_idx, hci->DAT_data); + if (hci->DAT_data) + __clear_bit(dat_idx, hci->DAT_data); } static void hci_dat_v1_set_dynamic_addr(struct i3c_hci *hci,